When retirement gets too stressful I take my camera and sit in my garden..... listening and watching, taking in the activity all around me. The birds, the breezes, the myriad variety of insects energetically buzzing about or those quietly and patiently waiting for a meal to stop by. On this sunny early summer day with all that was happening I was wondering. How does the biodiversity of a native plant garden compare with a typical urban garden? Seems to me that this would be an interesting study to quantify the overall diversity in various types of urban landscapes. But my thoughts on this were quickly diverted by the fascinating diversity here in my own garden and here are photos from my garden this early summer day.
Click on the photos to view them larger and with their captions.
Just completed this month was the harvest of the Farnsworth jewelflower fruits. These seeds with the mustang clover and speckled clarkia will be used in this autumn's reintroduction plots which I will be planting out on our property in Three Rivers.
This year after a a two year absence at our Three Rivers property I was quite delighted to see a good crop of Brodiaea elegans (harvest brodiaea) coming up and flowering. Pushing the seasonal fire safety limits I cut the grass leaving the brodiaea plants to finish flowering and go to seed. This selective process of being mindful of what and where to cut has allowed several local native species including several oak seedlings to start making a come back on our property.
Lastly for this post while sitting in my Hemet Garden I discovered several seedlings of our local Boechera californica (California rock cress). When I planted out some plants two autumns ago which I had grown from seed I collected locally I also cast some extra seed out and this year they are coming up. Being a local native this species is doing exceedingly well and I am happy to have it in my collection. Maybe some of the local insects and birds will be as well.
I will end this post with a photo I took of the early summer flowering of my sand verbena, the hybrid red flowering buckwheat, and the lovely orange desert mallow. It was a nice place to be today.
Wherever your garden is - get out and enjoy it.
The current drought has inspired many Californians to pull up their lawns, their thirsty garden shrubbery, and to become more receptive to alternative landscapes. Happily many re-landscapes are including our native plants, or if not natives, drought tolerant plants from other Mediterranean or desert regions of the world. There is however a common public misconception that because our plants are adapted to drought that they can be planted and once established left on their own for mother nature to care for.
So let's start with this test question. Choose the correct answer For the following statement: California native plants require....
A.) no supplemental irrigation
B.) supplemental irrigation a few times during the summer dry period
C.) regular weekly or twice a month irrigation during the dry season
D.) I don't know
Don't you wish "I don't know" was a test option when you were in school? Well for today's question D.) "I don't know" is the correct answer.
A plant's tolerance to drought - or in a garden setting the lack of supplemental irrigation - is conditional upon a great many factors but principally by the three which make up the magic triangle of horticultural: Provenance, Soil Type, and Climate. Actually there really is no such thing as a magic triangle of horticulture. Google it for yourself. I just made it up to serve my purpose here. These considerations are very important however and I will address each of them in more detail shortly. For now let's just state that while a majority of our native plants do have lower water requirements than conventional landscape plants they are not all created equal in their water thriftiness.
But before we get into our discussion just remember this: Watering your native plants too much or too little will either kill them or at best they will look really really ugly. Native plants are beautiful and if you are growing really ugly plants in your yard it gives California native plant gardening a bad rap. So we will all strive to provide just the right amount of supplemental water so our native plants will thrive and look as gorgeous as they should look!
So, how much and how often do you water native plants? Without understanding a little about your plant's provenance, your soil, and local climate there is no simple answer to this question. You pretty much have to figure this out for yourself and this process is called gardening.
But I want to help and not be snobby about this so let's get back to the magic triangle of horticulture noted in the diagram above and let's start with...
Provenance refers to an object's place or source of origin, or better stated, where did it come from? Why is this so important? A native plant's inclinations and preferences are encoded in their DNA by their provenance or where they evolved. So when we move plants from, say, their cool and moist place of origin to a hot and dry region, they need some help to be happy in their new environment.
Do keep in mind that a plant's provenance is not the nursery where they were grown or where you purchased them. The Irishman is not going to tan better just because he was born in southern California southern California. Right?
Here are two maps I have selected to help illustrate my point. You ask what point am I trying to make? OK, fair enough. Where our native plants come from, their provenance, (their Provenance) makes a big difference on how drought tolerant they will be. So now back to the maps. You can click on the map to view them larger. Do this, study the maps and the legends, and then we will continue. (a big thank you to Oregon Climate Service and NOAA)
So now you have memorized the maps. Good. For an example, let's use a very popular native landscape tree, the coast redwood (Sequoia sempervirens). Now these plants, even though they grow in the fog belt of California's pacific northwest, are quite adaptable and widely grown around the state in parks, along some freeways, and in many larger home gardens. Now they grow wonderfully with little to no supplemental irrigation near the central to northern coast (within their local provenance area) but bring them inland and they will require a whole lot of water to be happy and beautiful, i.e. not really really ugly. Remember, no ugly native plants. And if you live anywhere east or south of the central and north coast ranges and want to save water...do not plant sequoias. Choose something more local to your region.
For another example of how these maps and knowing a plant's provenance can help us to better coordinate our garden and maintain our plants, we will look at some plants in my garden. Beautiful aren't they?
Here in this view of my garden are a hybrid buckwheat (Eriogonum molle x fasciculatum), a silver sage brush (Artemisia ludoviciana), a salvia cultivar (Salvia 'Allen Chickering') and a desert mallow (Sphaeralcea ambigua). Now, these four plants thrive in my garden, all are drought tolerant, but only one is "local" or native to my part of California, i.e. of local provenance. The other three are imports, tourists, or immigrants, if you wish, who originated from other places in the state. Before I get into any specifics about the differences in these plants I want to answer the question which I am certain you have been wanting to ask. "How can we know where a plant comes from?" Well fortunately there are many good folks in the state who work very hard to maintain data bases of California plants. My favorite and easiest to use for this topic is Calflora. I have linked the silver sage and the desert mallow above to the Cal Flora website. Click on them and you will see a map which shows where in the state they have been documented growing naturally. You can then compare these sites with the temperature and precipitation maps to get a better idea of how suitable to your region a given plant might be.
I did not link the other two plants as being of hybrid origin they have a more complicated provenance. Cultivars and hybrids are not listed on Calflora so you have to know the parentage to find out their provenance. The Salvia is a hybrid between Salvia leucophylla and Salvia clevelandii. In my garden when the weather turns hot and soil moisture is low, even when this Salvia's leaves are curling from a lack of soil moisture, the foliage of the silver sage, which grows in a canyon about 12 miles from us (local provenance), and the desert mallow (desert provenance) are full and lush. If you look up Salvia leucophylla on the Calflora website you will find that it grows in the inner and outer south coast range, areas which, though it is quite dry and warm during the summer, are moderated by the local coastal influence. Salvia clevelandii from San Diego County grows mostly inland from the coast but at higher elevations in the Cleveland National Forest. So though my Salvia is nicely drought tolerant it requires more water in my warm inland valley area. In case you are curious about the buckwheat, the mom of this hybrid is from an island off the coast of Baja California (Eriogonum molle). However this selection growing in my yard is more like its dad, the common and very drought-tolerant California buckwheat (Eriogonum fasciculatum), and thus while it is not as resistant to drought as the silver sage or the desert mallow it is more so than the salvia. Making any sense?
The take home point here is that in general if you want to use less water in your landscape choose plants from your local region, desert plants, or if you can afford to, move closer to the coast.
Now, in my garden the soil is quite sandy and this brings us to the second of our Very Important Considerations: soil type.
Now learning about plants and geography is fun but studying soil is, well, pretty dull by comparison so I will keep this section really short. With my sandy soil having relatively large particles it does not compact and accepts and drains water quickly. Having large spaces between soil particles there is also less water retention and more air-holding capability. If I were growing my same plants in a heavier soil with more tightly packed moisture-holding clay or silt I would not have to water the Salvia as frequently. In fact, I would have to be wary that I do not drown the plants by filling in those teeny tiny air spaces with excess water. Too much moisture, especially in the warm months when our native plants are not accustomed to getting water, provides a great environment for root rot fungi, the bane and grim reaper of native plants.
So our take home point here is, the lighter and sandier your soil the more water you may need to provide your plants and the more frequently you will need to provide it. The heavier your soil the more slowly you need to apply water, and you need to be cautious not to over water your natives.
I could not find an author to credit for this illustration so to whomever made the soil particle drawing in this section, it is very nice. Thank you.
Climate and micro-climates are the last of the Very Important Considerations of the magic horticultural triangle. Thank you clipartpanda.com for this happy sun art work.
The region where you live and garden is affected by the local climate. I know, duh. But we Californians with our abundant water resources have been loathe to accept or even consider this. California is blessed with lots and lots of varied climates and the climate where you live and garden will have a strong bearing on how drought tolerant your plant will be. Additionally, no matter where you live your home and property also has micro climates, smaller regions where the bigger climate is varied by local conditions. Think the north and south sides of your home. Micro climate variation is also created by the shade of a tree or large shrub, and swales which receive more water from rains and cool air settling at night. Slope direction and sites protected from prevailing winds also create varied micro climates. I know we are not supposed to have leaky faucets, but even these create micro climates.
To illustrate, let's say you want to have a cactus collection at your home in San Luis Obispo. Well, this cool and often foggy coastal climate is not too ideal for desert plants. However, selecting a south- or west-facing slope for your plants, just as you would for your solar panels, will provide the warmest and driest site for your sun-loving succulents. Or take that flannel bush (Fremontodendron) that you have tried and tried to grow and repeatedly killed. Being that it is sensitive to summer watering try planting it on the well-drained and warm south- and west-facing slopes. And those water guzzling native willows, alder, redwood sorrel or creek monkey flower which you just have to have in your garden but which you also know you don't have any business trying to grow in your region? Maybe they should be relegated to the moist and more humid north side of your house or garden shed. You can also sneak them a little extra water late at night when no neighbors are watching.
Now there is nothing better than failure to teach us valuable lessons, right? For another example of the influence of micro climate here for all the world to read is my "I should have known better" lesson.
This is a specimen of Ceanothus 'Wheeler Canyon' which grew wonderfully in my garden for about 6 years and which I had planted on the east side of my house. Being cheap and lazy, when I installed my irrigation system I put the whole section on one valve, so when I ran it all the plants received about the same amount of water. As you can imagine, the soil nearest the house is shaded all afternoon and thus holds moisture much longer than the same soil 10 or 15 feet out. Thus, even with my well-drained-soil watering for my native plants in the outer hot and dry part of the garden, I over watered the Ceanothus and lost it to the grim reaper of native plants, root rot.
So the take-away lesson here is that micro climates provide us with opportunities that can and should be used to our advantage to get the most water savings from the plants in our gardens. And the more you garden with your local climate in mind, the less water your plants will need....and success will likely come more easily to you.
There is a popular food movement to buy local. So to get the most bang for your water buck and have a beautiful landscape, know your soil, garden within the limits of your climate, and grow local.
If there were such a thing as my favorite native plant it would likely be the clarkias. Their are 41 known species of clarkia and California is home to all but one species. Interestingly this species (Clarkia tenella) is found in far away South America. Many are rare, some endangered, and many species on those special California springs carpet whole hillsides. Here are photos of two species I am enjoying growing this year: Clarkia speciosa (red spot clarkia) and Clarkia gracilis subsp. tracyi (Tracy's clarkia).
There are so many good reasons to cultivate native plants in the garden but my personal favorite rationale for growing natives is that native plants are naturally better at creating urban habitat for other native species. The incredible diversity of life on our planet is something that human species have a way of diminishing. Creating diversity in our gardens provides food and shelter for native species and this is a way of showing appreciation and respect for other residents of our community. Watching the interactions and activities of plants and animals is also a great pleasure. I think the greatest bee attracting plant I have known is my Desert Museum parkincidium. Right now during the magnificent spring bloom from early morning to evening time there is a constant drone of activity by both honey bees and the western carpenter bee (Xylocopa californica). I rarely see carpenter bees except when this tree is in bloom and I wonder where they all come from. Parkincidium and this hybrid's parents, Parkinsonia (Mexican paloverde) and Cercidium (blue paloverde), are all excellent urban landscape trees thriving here in Hemet which is really a semi-desert region.
The other day at peak bloom just for fun I took my camera out and using a very small aperture, a slow shutter speed, and using my zoom mechanism I created these wacky abstract images hoping to emphasize the wonderful yellow of the flowers illuminated by the dazzling sunlight. They do however make me feel a bit dizzy looking at them.
This spring in the garden I am delighted to see my jewel flowers (Streptanthus farnsworthianus) flowering abundantly and producing large and hopefully very seedy fruits. In addition, from what I can tell, as the magnificent mustang clover winds down its boisterous bloom I am excited to see them also appearing to be setting seed. I am hopeful as when I pinch the individual ovaries, at the base of where the spent flower was, many are firm and plump indicating that pollination has occurred and seeds for my Three Rivers garden reintroduction project are developing within. While not big and showy both of these two native species viewed up close are absolute darlings in the garden and exceptionally photogenic.
This is Leptosiphon montanus, a California native annual wildflower more commonly known as mustang clover. Mustang clover is quite common in the wild occurring throughout the western slope of the Sierra Nevada mountains. Even in its native habitat however, where humans have built homes, it is rare or non-existent due primarily to non-native grass competition and wildfire safety maintenance practices. Although a very attractive annual mustang clover is also non existent in the horticultural trade. Could I do something about this? Is it garden compatible? Could I successfully reintroduce it to my blue oak woodland property in the Southern Sierra foothills of Three Rivers? Could I grow and multiply my meager seed stock at my home in Hemet, CA? What native plant gardener can resist this temptation - to bring the native wild flowers into their own gardens?
I have previously experimented with introducing local native annuals to both my properties including: Madia elegans subsp. vernalis (spring flowering madia), Lupinus nanus (sky lupine), and Nemophila menziesii (baby blue eyes) in Three Rivers.
And in my more desert environment in Hemet: Abronia villosa var. aurita (desert sand verbena), Boerhavia coccinea (scarlet spiderling), Bouteloua gracilis (blue grama grass), and Baileya multiradiata (desert marigold). The latter being a short lived but abundant and long blooming perennial.
Introducing these species to my two very different properties came about in a varied manner. For the woodland property I collected local source Madia seed from nearby populations, but the lupine and nemophila I purchased from Larner Seed. I would prefer to use all local source genotypes rather than purchasing seed but honestly I did not wish to wait until I could find them and I am only in this area infrequently. I started by solarizing several 6' x 6' plots. In the fall of 2012 I sowed the seed on roughed up but untilled soil and raked the seed in, and then prayed for timely rains. 2013 was excellent and all three species did very well but the plants in the spring of 2014 were not as abundant. This coming spring I should have a better idea how well the reintroduced natives will establish and be able to compete with the non-native grasses. For fire safety as the grasses dried out I trimmed around the natives which were still producing their seeds for next season and mowed them down at a later date. Below are some of the Nemophila cradling sleeping native bees.
Except for the desert marigold the seed for the Hemet property was acquired from local wild sources. The marigold, verbena, blue grama, and scarlet spiderling seed was simply scattered about and raked into the sandy soil. All four germinated readily but unlike most natives these germinated best in the warmer summer months and with a bit of "monsoonal" summer water. The verbena actually took several years before I noticed seedlings coming up thus an inherent dormancy mechanism must have been inhibiting germination. Very likely the heavy fruit coat. As seedlings often come up where you do not necessarily want them I found that all four species, if dug early, could be transplanted and moved around the yard as necessary. I installed a small cage around each one with shade cloth for protection if the weather was warm which summers in Hemet always are.
I am also experimenting with a number of other species. Just this past summer I raised up a box full of Clarkia cylindrica subsp. clavicarpa (speckled clarkia) in order to multiply the small collection of seed which I obtained from the Salt Creek populations near our Three Rivers home. Like all Clarkia species this one too is very showy, one of the standout dominant annuals in the Kaweah River drainage, and one that we wanted to reintroduce to our yard. Again this past summer I solarized several plots and this fall I sowed the clarkia seed.
On a small disturbed section of the property where a load of decomposed granite was dumped I also sowed purchased seed of several native grasses. The species which did well were Elymus glaucus (blue wild rye), and Stipa pulchra (purple needlegrass). Again here I simply roughed up the soil, sowed the seed and raked it in. In a separate site a small patch of Stipa cernua (nodding needlegrass) which I seeded in two years ago has thus far been hanging on and most lovely - but not naturalizing yet. I will likely learn much from these early attempts and hope to document over time on both my successes and failures.
So, back to where I started with the mustang clover. Here are some images of my seed regen boxes. They have worked very well for me to regenerate seed stocks of many different annual species. The boxes are made of recycled cedar fencing, measure 18" square, 7" deep, and have a 1/4 mesh hardware cloth bottom on which I layer newspaper to hold the soil. Three strips of wooden cleats keep the boxes off the ground and less likely to be invaded by ants and various other pests. The ropes were an idea I had after straining myself attempting to move these cumbersome and rather heavy boxes. The ropes allow me to easily drag the boxes about to sunnier or more shady locations, or just to move them to storage areas after the harvest season. The metal fencing is basically just to keep my dog out and the neighborhood cats from using them as litter boxes. Here are current photos of the mustang clover in progress and other lovely flowers I have grown using this method.
Enjoy your local flora - and the fauna which it brings - in the wild and in your own yard.
CNPS San Gabriel Chapter native plant sale Saturday November 8th 9:00 - 2:00. Plant sales are as much about people as about plants, especially the smaller CNPS chapter ones. Very dynamic and fun events.
Michael Wall - Hemet, CA